http://articles.sfgate.com/2007-01-19/bay-area/17228601_1_proteus-vessel-hulls
Yes, I commute on the ferry occasionally. Several years back, on the way home one evening we passed by this craft as it was sitting stationary off Angel Island. There hadn't been any press that I had seen up to that point, so naturally we all thought it was a super-secret DARPA project that we'd stumbled across, and that our ferry would probably be diverted to Area 51, our wives never to see us again.
Carl Nolte, who wrote this article, writes regularly about maritime subjects. He recently did a series of articles about the dissolution of the mothball fleet, and just last week a piece about the lightship San Francisco that is being given away, including two years free maintenance, to anyone interested.
I'd recommend bookmarking SFGate, the Chronicles website, for those stories.